<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        var websocket = null;
        var host = document.location.host;
        // var host = document.location.hostname+":"+8082
        var username = "admin"; // 获得当前登录人员的userName
        //判断当前浏览器是否支持WebSocket
        if ('WebSocket' in window) {
            console.log("浏览器支持Websocket")
            var url = 'ws://'+host+'/webSocket/'+username
            console.log(url)
            websocket = new WebSocket(url);
        } else {
            console.log('当前浏览器 Not support websocket')
        }

        //连接发生错误的回调方法
        websocket.onerror = function() {
            console.log("WebSocket连接发生错误")
            setMessageInnerHTML("WebSocket连接发生错误");
        };

        //连接成功建立的回调方法
        websocket.onopen = function() {
            console.log("WebSocket连接成功")
            setMessageInnerHTML("WebSocket连接成功");
        }

        //接收到消息的回调方法
        websocket.onmessage = function(event) {
            console.log("接收到消息的回调方法")
            setMessageInnerHTML("后台推送的消息："+event.data);
            websocket.send("已收到"+event.data+"的消息");
            // websocket.close();
            // alert("webSocket已关闭！")
        }

        //连接关闭的回调方法
        websocket.onclose = function() {
            setMessageInnerHTML("WebSocket连接关闭");
        }

        //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
        window.onbeforeunload = function() {
            closeWebSocket();
        }

        //关闭WebSocket连接
        function closeWebSocket() {
            websocket.close();
        }

        //将消息显示在网页上
        function setMessageInnerHTML(innerHTML) {
            document.getElementById('message').innerHTML += innerHTML + '<br/>';
        }
    </script>
    <style type="text/css">
        div{
            text-align:center
        }
        .center-in-center{
            /*position: absolute;
            top: 50%;
            left: 43.2%;*/
        }
    </style>
</head>
<body>
<div id="message" class="center-in-center">

</div>
</body>
</html>